Adsorption of sodium dodecyl benzene sulfonate surfactant from aqueous solutions using magnetic graphene oxide nanocomposite functionalized with chitosan

This study investigated the removal of sodium dodecyl benzene sulfonate (SDBS) from aqueous solutions using a chitosan-functionalized magnetic graphene oxide nanocomposite. Graphene was initially synthesized from lignocellulose waste, followed by oxidation and magnetization. The material was subsequently functionalized with chitosan extracted from shrimp shells. The structural properties of the synthesized nanoparticles were characterized using FE-SEM, VSM, AFM, and Raman spectroscopy, which confirmed successful synthesis and functionalization. Batch adsorption experiments were conducted to evaluate the effects of pH, adsorbent dosage, contact time, and temperature. The results showed a maximum experimental adsorption capacity of approximately 65 mg/g. The adsorption isotherm was best described by the Langmuir model, indicating monolayer adsorption on a homogeneous surface. Kinetic studies revealed that the adsorption process followed the pseudo-second-order model. Thermodynamic analysis confirmed that the adsorption of SDBS was endothermic and spontaneous. The synthesized nanocomposite demonstrated a relatively high adsorption capacity for SDBS, suggesting its potential for economic recovery and reuse in wastewater treatment systems. The adsorption mechanism was found to be governed by a combination of electrostatic interactions and surface complexation, indicating a mixed physical–chemical adsorption process.